Interesting, if you look at the
footnotes for the statement,
The wounds produced by the M193 round were so devastating that many[12] consider it to be inhumane.[13][14]
Two of them refer to "International Legal Initiatives to Restrict Military Small Arms Ammunition, W. Hays Parks∗ Copyright 2010 by W. Hays Parks" and footnote makes the claim that "Austria, Argentina, Belgium, Bolivia, Bulgaria, Burundi, Cambodia, Cyprus, Germany, Ireland, Latvia, Lithuania, Luxembourg, Mauritius, Mexico, Romania, Samoa, Slovenia, Sweden, Switzerland, etc. as parties that consider the 55 gr M193 round to be inhumane"
Well, that document is available from the U.S. Defense Technical Information Center here:
http://www.dtic.mil/ndia/2010armament/TuesdayLandmarkBHaysParks.pdf
And that is not what the document actually says. Only one nation argued against the M193, Sweden:
International Legal Initiatives to Restrict Military Small Arms Ammunition W. Hays Parks∗ Copyright 2010 said:
First was Sweden’s opposition to United States’ support for the Government of the Republic of Viet Nam against the war being waged against it by the Democratic Republic of Viet Nam. Although that conflict had ended, the U.S. M16 rifle in part was seen as symbolic of that war and one of many weapons critic ized by Sweden during that conflict.
Second, exaggerated terminal ballistics claims by Colt to sell their weapons to the U.S. military provided Sweden and other perpetual U.S. critics political “ammunition” to challenge the legality of the U.S. 5.56x45mm cartridge and weapons systems, alleging “inhumane” wounding.
Finally, the Swedish arms industry had its 4.5x26R MKR assault rifle under belated development for the on-going NATO second rifle caliber competition. Realizing the U.S. 5.56x45mm caliber and other competing cartridges (the Belgian 5.56x45 SS-109, French 5.56x45mm steel case with M-193-type projectile, Netherlands M-193 type, British 4.85mm and German 4.7mm) had a head start in consideration, the 5.56 “legality” issue was intended to slow the second rifle caliber decision as Sweden continued development of its candidate. It became all for naught when NATO adopted the 5.56x45mm (Belgian SS-109) as its second caliber on October 28, 1980.
Switzerland later complained about the 5.56 round in general, not the M193 in specific.
There is some other stuff in there on how the ICRC was trying to get into the international lawmaking business. Interesting read.